Lead stabilization devices and methods

ABSTRACT

Devices and methods for stabilizing a lead in a cardiac vein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/510,663, filed Oct. 10, 2003, entitled LEADSTABILIZATION DEVICES AND METHODS to Atkinson et al., the entiredisclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to medical devices and methods.More specifically, the present invention relates to medical devices andmethods for stabilizing leads in cardiac vasculature.

BACKGROUND OF THE INVENTION

Heart failure is an increasingly common condition worldwide. Cardiacresynchronization therapy (CRT) has shown great promise as a treatmentfor a large percentage of patients in various stages of heart failure.CRT involves cardiac pacing of both the left and right ventricles of theheart (biventricular pacing), which causes both ventricles to beatsimultaneously, greatly improving the pumping efficiency of the heart.Typically, the lead that stimulates the left ventricle is positioned viathe coronary sinus into a cardiac vein along the free wall of the leftventricle.

There are numerous challenges in successfully positioning the leftventricular lead, including accessing the coronary sinus and veins,advancing the leads to a position which yields proper stimulation, andpreventing subsequent lead dislodgement during removal of deliverydevices. Post procedural challenges related to the left ventricular leadinclude lead dislodgement prior to fibrosis, loss of stimulationcapture, and lead removal necessitated by infection.

Currently available left ventricular leads have generally been designedto facilitate effective delivery and provide fatigue resistance, and areparticularly susceptible to dislodgement both intra-procedurally andpost-procedurally. Efforts to incorporate more aggressive anchoring intothe lead body have generally been insufficient for preventingdislodgment, and/or have compromised effective delivery, fatigueresistance and subsequent lead removal.

SUMMARY OF THE INVENTION

Therefore, a need exists to enable effective lead stabilization withoutcompromising lead delivery, resistance to lead fatigue, or lead removal.To address this need, various exemplary non-limiting embodiments aredescribed herein which provide devices and methods for acute and/orchronic lead stabilization. By way of example, not limitation, the leadstabilization mechanisms described herein may be separate from butcooperative with the lead, thus allowing independent delivery andfunction. To this end, the lead may be designed for effective deliveryand fatigue resistance, and the stabilization mechanism may be designedfor effective acute and/or chronic anchoring to prevent leaddislodgement. In addition, the stabilization mechanisms described hereinmay be separable from the lead to permit subsequent lead removal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an anterior view of a human heart and associated vasculature;

FIG. 2 is a posterior view of a human heart and associated cardiacvenous vasculature;

FIG. 3 is a schematic side view of a lead and an anchor device in theform of a stent disposed in a cardiac vein;

FIG. 4 is a schematic side view of a lead and an alternative anchordevice in the form of a stent disposed in a cardiac vein;

FIG. 5 is a schematic side view of a lead disposed in a coronary veinand an alternative anchor device in the form of a stent disposed in asecondary cardiac vein;

FIG. 6 is a schematic side view of an anchor delivery device for use indelivering the anchor devices illustrated in FIGS. 3-5;

FIG. 7 is a schematic side view of a lead and an alternative anchordevice in the form of a coil disposed in a cardiac vein;

FIG. 8 is a schematic side view of a lead and an alternative anchordevice in the form of a bundle disposed in a cardiac vein;

FIG. 9 is a schematic side view of a lead disposed in a cardiac vein andan alternative anchor device in the form of a plug disposed in asecondary cardiac vein;

FIGS. 10 and 11 are schematic side views of a lead and alternativeanchor devices in the form of wedges disposed in a cardiac vein;

FIG. 12 is a schematic illustration of a release mechanism in the formof a connector cutter;

FIG. 13 is a schematic side view of a lead disposed in a cardiac veinand an anchor device in the form of a coiled stent disposed near theostium of the coronary sinus;

FIG. 13A is a cross sectional view taken along line A-A in FIG. 13;

FIG. 13B is side sectional view of the fastener illustrated in FIG. 13;

FIG. 14 is a schematic side view of a lead disposed in a cardiac veinand an anchor device in the form an anchor catheter; and

FIG. 15 is a detailed schematic view of the anchor catheter illustratedin FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention.

With reference to FIGS. 1 and 2, the anatomy of a human heart (H) isillustrated. FIG. 1 shows the heart from the anterior side, with theright chambers of the heart shown in section. FIG. 2 shows the heartfrom the posterior side, and illustrates the cardiac veins, includingthe coronary sinus (CS) and its associated venous branches (greatcardiac vein, left marginal vein, left posterior ventricular vein,middle cardiac vein, and small cardiac vein). The CS carries the primaryvenous return for the cardiac circulation, with the venous branchesdistributed about the heart and draining into the CS. The CScircumnavigates the left side of the heart, generally between the leftatrium (LA) and the left ventricle (LV). The CS drains into the rightatrium (RA) at the ostium.

Left ventricular leads are typically implanted with the proximal endconnected to a pulse generator in a subcutaneous or submuscular pocket,and the distal end (electrode(s)) disposed in one of the cardiac veinsto stimulate the left ventricle. The lead body typically extends fromthe pulse generator in the subcutaneous or submuscular pocket, throughthe vein wall and into the left subclavian vein (LSV), through the leftbrachio-cephalic vein (LBV), down the superior vena cava (SVC) and intothe right atrium (RA), into the CS and into the target cardiac vein. Thevenous circulation is usually accessed by introducing delivery catheters(called guide catheters or guide sheaths) from a venous arteriotomy inthe LSV to the CS ostium, following the dashed line shown in FIG. 1.Once the CS is cannulated by a delivery catheter, a coronary venogram isobtained to visualize the cardiac veins. The lead is advanced into theCS and the desired cardiac vein, following an exemplary path indicatedby the dashed line shown in FIG. 2.

There are generally two categories of LV leads, over-the-wire (OTW)leads and stylet-delivered leads. OTW leads incorporate a guide wirelumen which extends through the entire lead body, emerging at the tip ofthe lead. Navigation within the CS and cardiac veins is performed byadvancing a steerable guide wire to a desired location in a cardiacvein, and the lead is then advanced over the guide wire. Styletdelivered leads have a stylet lumen which extends through the lead body,but typically terminates proximal of the distal tip. A shaped styled ispositioned in the stylet lumen and the lead and stylet are advancedtogether to navigate the lead to a desired location in a cardiac vein.

Once the lead is positioned in a location that yields acceptablestimulation (capture), the delivery catheter is removed. Depending onthe particular lead, and the type of electrical connector utilized,removal is accomplished either by withdrawing the delivery catheter overthe proximal end of the lead, or by splitting the delivery catheter asit is removed over the proximal end of the lead. In some situations,removal of the delivery catheter may dislodge the lead, as the stabilityof the lead position is often quite tenuous. Even if the lead is notdislodged during removal of the delivery catheter, the beating of theheart and other patient activities can cause lead movement ordislodgement, leading to potential loss of capture (effective pacing ofthe LV).

With reference to FIG. 3, a pacing lead 10 and an anchor device in theform of a stent 20 are schematically shown disposed in a cardiac veinCV. Generally, the CV generically refers to venous braches of thecoronary sinus such as the great cardiac vein, left posteriorventricular vein, middle cardiac vein, small cardiac vein, or othercardiac vein that leads to the left ventricle, and preferably that leadsto the apex of the left ventricular free wall or that otherwise providesfor effective pacing of the left ventricle. Those skilled in the artwill recognize that because of anatomic variation, the precise name andposition of the CV will vary.

Lead 10 may comprises a conventional pacing lead having an elongate bodyor shaft 12 and one or more electrodes 14 connected to a pulse generator(not shown) by corresponding wires or traces inside the lead body 12.Lead 10 is generally designed to be very flexible and fatigue resistantto permit free cardiac movement, to minimize tissue trauma, and towithstand repeated flexure primarily caused by the beating heart. Theelectrodes 14 are typically positioned on or near the wall of the veinfacing the heart to establish effective conduction into the heart wall.

Stent 20 may be self-expandable or balloon expandable, for example, andmay be formed of a biocompatible metal material such as stainless steel,Nitinol, Elgiloy, or MP35N. Alternatively, stent 20 may be formed of abiodegradable polymeric material such as poly-L-lactic acid,polyglycolic acid, or polycaprolactone, or other biodegradable materialssuch as those used for biodegradable sutures. In the case of polymericmaterials used for stent 20, the polymer may be loaded with a radiopaqueagent such as barium, bismuth subcarbonate, etc. to facilitate x-rayvisualization. Generally speaking, all of the anchors of the anchordevices described herein may be formed of the aforementioned materialsand may be radiopaque.

Stent 20 may be connected to lead 10 by an elongate connector 30.Elongate connector 30 may comprise a tether that is flexible and fatigueresistant such as a braided cord of a high strength biocompatiblepolymer such as polyester, polypropylene, or polyethylene (e.g., Spectrabrand), and may be partially or fully covered or coated with a materialthat promotes tissue in-growth such as ePTFE. The tissue in-growthpromoting material may serve to secure the elongate member 30 to thelead 10 and/or prevent bacteria migration along the elongate member 30.

In the embodiment illustrated in FIG. 3, the elongate member or tether30 extends through the lumen (e.g., guide wire lumen) of the lead 10.This embodiment is particularly suitable for OTW leads that typicallyhave a guide wire lumen extending therethrough. The proximal end of thetether 30 may extend out the proximal end of the lumen of the lead 10,and may be connected to the lead 10 by tying a knot that is larger thanthe diameter of the lumen, for example. Alternatively, the proximal endof the tether 30 may be connected to the proximal end of the lead 10 bytrapping the tether 30 in the lumen of the lead 10 with a wedge orpinching it between the electrical connector of the lead 10 and thesocket of the pulse generator. The distal end of the tether 30 may beconnected to the stent 20 by tying the tether 30 in a knot around astrut of the stent 20, or swaging and end of the tether 30 betweenstruts of the stent 20, for example.

In this embodiment, the stent 20 and tether 30 may be deployed beforethe lead 10 is delivered. The stent 20 may be deployed in a distalportion of the target CV with a delivery device as described in moredetail with reference to FIG. 6. Once deployed, the proximal end of thetether 30 may be inserted into the distal end of the lumen extendingthrough the lead 10, and the lead 10 may then be advanced over thetether 30 and into the CV to the desired position, and pacing tests maybe performed to ascertain LV pacing capture. Once the lead 10 is in thedesired position, the proximal end of the tether 30 may be secured tothe proximal end of the lead 10 as described previously.

If it is necessary or desired to remove or reposition the lead 10, thelead 10 may be removed from the CV by disconnecting the tether 30 fromthe lead 10 (e.g., by cutting the knot in the tether 30 at the proximalend of the lead 10), the tether 30 may be removed from the CV bydisconnecting the tether 30 from the stent 20 (e.g., by using a cuttingdevice as described in more detail with reference to FIG. 12), and thestent 20 may be left in place in the CV without compromising blood flowthrough the CV.

With reference to FIG. 4, an alternative anchor device arrangement isshown schematically. In this embodiment, rather than extending throughthe lumen of the lead 10, the tether 30 extends along side the lead 10.This embodiment is particularly suitable for stylet-delivered leads thattypically do not have a lumen extending therethrough, but may be usedwith either stylet-delivered or OTW leads. This embodiment also allowsfor the delivery of the anchor device either before or after lead 10placement.

The tether 30 may be connected to the lead 10 by a fastener such ascollar 40. Collar 40 may comprise a short dual lumen tube including arelatively large lumen to accommodate the lead 10 therethrough and arelatively small lumen to accommodate the tether 30 therethrough. Collar40 may be fixedly connected to the lead 10 if the anchor device isdelivered prior to the lead 10 by swaging, adhesive, etc. To facilitatedelivery of the lead after placement of the lead 10, the collar 40 maybe slidable over the lead 10 and lock in place adjacent the distalpotion of the lead 10 using a mating geometry such as a detent on theouter surface of the lead 10 that receives a protrusion extending fromthe inside surface of the collar 40. Alternatively, the outer surface ofthe lead 10 may include a protrusion such as a stepped ridge 45 thatabuts the distal end of the collar 40 as the collar 40 is advanced overthe lead 10 in order to prevent proximal movement of the lead 10relative to the collar 40. With this alternative, the stepped ridge 45may be an integral extension of the outer surface of the lead 10 or aseparate component fixedly connected to the lead 10.

The tether 30 may be effectively connected to the collar 40 to preventproximal movement of the collar 40 relative to the tether 30 byutilizing a knot or stop 35 that is slid down the length of the tether30. A knot may be made in the tether at its proximal end and advanceddistally to the collar 40 using a conventional knot pusher. A stop 35may be used and configured to readily advance distally over the tether30 and resist retraction proximally. For example, stop 35 may comprise ashort tubular segment having proximal facing flanges extending from theinside surface that selectively engage the tether 30 only when the stop35 is advanced in the proximal direction relative to the tether 30. Tofacilitate removal of the lead 10, the stop 35 may be cut or the tether30 may be cut between the stop 35 and the collar 40 using the cuttingdevice described with reference to FIG. 12.

To facilitate advancement of the collar 40 over the lead 10 and tofacilitate advancement of the stop 35 over the tether 35, a dual lumenadvancement sheath 50 may be slid (pushed) over the lead 10 and tether30. Sheath 50 may comprise an elongate dual lumen tube having a lengthsufficient to extend over the lead 10, through the venous vasculature,and out the venous access site, with one lumen to accommodate the lead10 and another lumen to accommodate the tether 30. Sheath 50 may includea slit (not shown) along the length thereof to facilitate peeling overthe lead 10. Sheath 50 may be removed over the lead 10 and tether 30after advancement of the collar 40 and stop 35, or it may be leftimplanted to contain the tether 30 relative to the lead 10.

With reference to FIG. 5, an alternative anchor device arrangement isshown schematically. In this embodiment, the stent 20 is deployed in asecondary cardiac vein (SCV) and connected via tether 30 and collar 40to lead 10 as described with reference to FIG. 4. Positioning the stent20 in a SCV enhances the anchoring effect and, because of collateralvenous circulation, reduces the possibility of adverse effects if thestent 20 were to become occluded.

With reference to FIG. 6, a schematic side view of an anchor deliverycatheter device 100 for use in delivering anchor devices such as stent20 as described in connection with the embodiments of FIGS. 3-5. In thisembodiment, the delivery device 100 is configured to deliver anelastically expandable (self-expanding) stent, but a balloon cathetertype delivery device may alternatively be utilized to deliver aplastically deformable (balloon expandable) stent. In the illustratedembodiment, the delivery catheter 100 may include an inner tube 110coaxially disposed in an outer tube 120. The stent 20 may be pre-loadedinside the outer tube 120, near its distal end. The distal end of theinner tube 110 abuts the proximal end of the stent 20, and may beadvanced distally with respect to the outer tube 120 as indicated byarrow 115 to advance stent 20 out of the distal end of the outer tube120. The tether 30 may be disposed between the inner tube 110 and theouter tube 120.

To facilitate delivery, a guide wire 130 may be used to initiallynavigate the CV. Once the guide wire 130 is in the desired position, thedelivery catheter 100 with the pre-loaded stent 20 therein may then beadvanced over the proximal end of the guide wire 130 and advancedthereover to the desired deployment position. The inner tube 110 may beadvanced in the distal direction with respect to the outer tube 120 asindicated by arrow 115 to deploy the stent 20 in the CV. Once the stent20 is deployed, the delivery catheter 100 may be removed.

With reference to FIG. 7, an alternative anchor device arrangement isshown schematically. In this embodiment, a coil 70 is deployed distal ofthe lead 10 and connected via tether 30 to lead 10 as described withreference to FIG. 3. The proximal end of the coil 70 may be connected tothe distal end of the tether 30 at connection 75, and the coil 70 maycomprise a resilient structure such as a metal wire formed of any of thematerials described with reference to stent 20. Coil 70 may be deliveredvia a lumen (e.g. guide wire lumen) extending through the lead 10 and isparticularly suitable for an OTW lead. The coil 70 may be advancedthrough the lumen of the lead 10 using a push tube (not shown) havingsufficient column strength disposed over the tether 30 that abuts theconnection 75 between the coil 70 and the tether 30.

To accommodate delivery through the lumen extending through the lead 10,the coil 70 may have a delivery configuration wherein the coil 70 iselongated to have a reduced profile sufficiently small to fit into thelumen, and a deployed configuration wherein the coil 70 is radiallyexpanded to have an expanded profile sufficiently large to frictionallyengage the wall of the CV. The coil 70 may be highly elastic such thatit assumes the deployed configuration automatically upon advancement outof the distal end of the lead 10, or the coil may be actuated (e.g.,thermally) upon advancement out of the distal end of the lead 10 toassume the deployed configuration.

With reference to FIG. 8, an alternative anchor device arrangement isshown schematically. In this embodiment, a bundle 80 is deployed distalof the lead 10 and connected via tether 30 to lead 10 as described withreference to FIG. 3. The proximal end of the bundle 80 may be connectedto the distal end of the tether 30 at connection 85, and the bundle 80may comprise a resilient structure such as a metal wire formed of any ofthe materials described with reference to stent 20. Bundle 80 may bedelivered in the same manner as and may have the same or similarcharacteristics as coil 70 described with reference to FIG. 7. Bundle80, as opposed to coil 70, may have an occlusive effect, and thereforemay be particularly suitable for a SCV to take advantage of collateralvenous circulation.

With reference to FIG. 9, an alternative anchor device arrangement isshown schematically. This embodiment is similar to the embodimentillustrated in FIG. 5, except that a plug 90 is used in place of stent20. The plug 90 may comprise a curable adhesive (e.g., cyanoacrylate,EVA in a DSMO solvent) or an embolic coil, for example, such as thoseconventionally used in occluding blood vessels and aneurisms. Plug 90may be deployed in a SCV using a conventional embolic delivery systemand connected via tether 30 and collar 40 to lead 10 as described withreference to FIG. 4. Positioning the plug 90 in a SCV enhances theanchoring effect, and despite the occlusive effect of the plug 90, thepossibility of adverse effects are reduced if not eliminated due tocollateral venous circulation.

With reference to FIGS. 10 and 11, alternative anchor devicearrangements are shown schematically. In these embodiments, a wedge 140or 150 is deployed adjacent the distal portion of the lead 10, such asproximal of electrodes 14. Wedges 140 and 150 frictionally engage thelead body 12 and the wall of the CV, to lodge the lead 10 in the desiredposition in the CV. The wedges 140 and 150 may be connected to tether 30to facilitate subsequent removal. Wedges 140 and 150 may comprise any ofthe materials discussed with reference to stent 20. Wedges 140 and 150are particularly suitable for deployment after the lead 10 has beendelivered to the desired position.

With specific reference to FIG. 10, wedge 140 includes a body portion142 and optional threads 144. Body portion 142 may include a perfusionlumen extending therethrough to permit blood perfusion from the distalend to the proximal end of the wedge 140. The wedge body 142 (or thewedge threads 144 if used) may have a diameter slightly greater than thediameter of the lumen of the CV less the diameter of the lead 10 inorder to provide a snug frictional fit therebetween. Wedge 140 may bedelivered into the desired position utilizing a push tube 60 advancedover a guide wire (not shown), for example, wherein the push tube 60 hassufficient column strength to push the wedge 140 alongside the lead 10with the distal end 65 of the push tube abutting the proximal end of thewedge 140 and the tether 30 extending through the push tube. The pushtube may also have sufficient torsional strength with a distal end 65that mates with the proximal inside diameter of the wedge 140 such thatthe wedge 140 may be rotated to engage or disengage the threads 144 withthe lead 10 and the wall of the CV.

With specific reference to FIG. 11, wedge 150 comprises a short duallumen having one lumen to accommodate the lead 10 and another (crescentshaped) lumen to permit blood perfusion from the distal end to theproximal end of the wedge 150. The wedge 150 may be tapered and may havea diameter slightly greater than the diameter of the lumen of the CVless the diameter of the lead 10 in order to provide a snug frictionalfit therebetween. Stepped ridge 45 prevents proximal movement of thelead 10 relative to wedge 150 as described previously. Wedge 150 may bedelivered into the desired position utilizing a push tube 50 advancedover the lead 10, as described previously.

With reference to FIG. 12, a cutting device 160 is shown schematically.Cutting device 160 may be used to cut tether 30 and/or stop 35 in orderto disconnect the tether 30 from the anchor device, such as stent 20.Cutting device 160 is merely an example of a variety of cuttingmechanisms that may be used to sever the connection of the tether 30from the anchor device. For example, the tether 30 may be equipped withtwo internal wires connected to a distal electrolytic fuse thatseparates (melts) upon the application of electrical current, such asthose used for detachable embolic coils.

In this exemplary embodiment, cutting device 160 includes an outer tube162 and an inner tube 164 coaxially disposed and movable therein. Theouter and inner tubes 162 and 164 may have a length sufficient to extendfrom outside the vascular access site to the anchor device, and may beconfigured for intravascular navigation and advancement over tether 30.The distal end of the inner tube 164 may have a sharpened edge and maybe formed of a material that retains a cutting edge (e.g., metal). Acutting hole 168 is provided adjacent the distal end of the outer tube162 through which the tether 30 may be threaded. The distalcircumference of the cutting hole 168 may be sharpened and may be formedof a material that retains a cutting edge (e.g., metal) After thecutting device is advanced over the tether 30 to the desired cuttingsite, the inner tube 164 may be advanced distally as indicated by arrow166, with the sharpened distal end of the inner tube 164 and thesharpened cutting hole 168 acting as shears to cut the tether 30 at thecutting hole 168.

With reference to FIG. 13, a lead 10 is shown disposed in a CV, with ananchor device in the form of a coiled stent 200 disposed near the ostiumof the CS. The coiled stent 200 may be positioned near the ostium of theCS, where the vessel diameter is large enough to resist becomingoccluded by the presence of the coiled stent 200 next to the lead 10.However, it is contemplated that the coiled stent 200 may be placedelsewhere within the CS or CV in which the lead is positioned. As seenin FIG. 13A, the lead 10 is eccentrically disposed in the lumen of theCS to define a relatively large crescent shaped blood perfusion lumen.

Coil stent 200 may be formed of a resilient material such as Nitinol,Elgiloy, MP35N, or stainless steel. Coiled stent 200 could also beformed of degradable materials such as those described in reference tostent 20 above. Coiled stent 200 may be releasably attached to the lead10 utilizing collar 210, and collar 210 may frictionally engage the body12 of lead 10, thus facilitating anchoring of the lead within thecoronary sinus or cardiac vein.

With reference to FIG. 13B, the collar 210 may comprise a relativelyshort tube 212, and may include one or more proximally oriented grips218. Grips 218 may be in the shape of finger-like projections, orcircular ribs either partially or completely extending circumferentiallyaround the inside of tube 212. Grips 218 facilitate the advancement ofthe collar 210 in a distal direction for delivery over lead 10, butresist proximal movement once the collar 210 is positioned in a desiredanchoring location. Grips 218 may be formed of a soft resilient materialsuch as silicone, polyurethane, polyether-block-amide, or the like.

To facilitate subsequent removal of the lead 10, the coiled stent 200may be connected to the collar 210 in a detachable manner. For example,the coiled stent 200 may be connected to the collar 210 utilizing abiodegradable adhesive connecting adjacent portions of the coil 200 tothe collar 210. Such an adhesive may degrade after the lead 10 haschronically anchored to the wall of the CS by normal tissueencapsulation. After the adhesive has degraded, the lead 10 (along withcollar 210) may be removed utilizing standard techniques, with thecoiled stent 200 remaining in the CS.

Alternatively, the coiled stent 200 may be secured to the collar 210utilizing a retractable pin 220. In this alternative embodiment, collar210 may include two angled flanges 214 collectively defining a recess216 in which stent coil 200 may reside. Pin 220 may span the length ofthe recess 216 between the flanges 214, extending over the coiled stent200 to retain the coil stent 200 in the recess 216, thus providing aconnection between the stent coil 200 and the collar 214. Subsequentrelease of the stent coil 200 from the lead 10 may be accomplished byremoving pin 220 using tether 30 which extends from the proximal end ofthe lead 10 to the pin 220. The proximal end of the pin 220 is connectedto the distal end of the tether 30, and the pin 220 may be removed bypulling the tether 30 proximally. After the pin 220 is removed, the lead10 and collar 210 are free from the stent coil 200 and may be removedwith standard techniques, leaving stent coil 200 in the CS.

Delivery and deployment of the stent coil 200 and collar 210 may befacilitated by deployment sheath 230. The deployment sheath 230 maycomprise a tubular catheter, having a lumen extending therethrough toaccommodate the lead 10 and the stent coil 200. Alternatively, the lumenin the deployment sheath 230 may extend from a distal opening to amid-shaft opening as used in conventional monorail style ballooncatheters. After lead 10 has been positioned by standard techniques to adesired position, the stent coil 200 and collar 210 may be loaded on theproximal end of the lead 10. Coil 200 may be initially in a compressedcondition, and loaded in the inside of the deployment sheath 230. If thelead 10 has a large diameter proximal connector, an optional slit 215may be provided in the collar 220 to facilitate loading over the largediameter connector. In this case, the collar 210 and coil 200 may bepositioned on the lead body 12 before the coil 200 is loaded into thedeployment sheath 230. The deployment sheath 230 may be advanceddistally down the body 12 of the lead 10 until the stent coil 200 andcollar 210 are in the desirable location. The deployment sheath 230 maythen be withdrawn proximally, with the collar 210 and stent coil 200remaining in position on the lead 10 due to grips 218 on collar 210. Asthe stent coil 200 emerges from the deployment sheath 230, it expands toengage the wall of the CS. The deployment sheath 230 can then be removedfrom the lead 10.

FIGS. 14 and 15 illustrate an anchor device in the form of an anchoringcatheter 300, which may be utilized to secure the position of lead 10,particularly during the removal of the guide sheath (guide catheter)used in the delivery of the lead 10. As described above, the leadstability is particularly vulnerable during the removal of the guidesheath.

In use, the anchoring catheter 300 is positioned next to the lead 10after lead 10 has been positioned in a desired location. Anchoringcatheter 300 may be advanced within the guide sheath (not shown),generally parallel to the lead body 12, or may be advanced outside theguide sheath. An expandable member such as a balloon 314 is inflated tofrictionally secure lead 10 against the wall of the blood vessel. Theguide sheath can then be removed without inadvertent dislodgement of thelead 10. The anchoring catheter 300 can then be removed. Since anchoringcatheter 300 is next to and not surrounding the lead body 12, removal ofthe anchoring catheter 300 does not pose a risk of dislodging lead 10.

With particular reference to FIG. 15, anchoring catheter 300 is shown inmore detail. Shaft 312 may comprise a proximal shaft portion 312Aconnected by adhesive, for example, to a distal shaft portion 312B. Aluer adaptor 316 may be connected to the proximal end of the proximalshaft portion 312A for connection to an inflation apparatus (not shown)such as a syringe. An inflatable balloon 314 may be connected to thedistal end of the distal shaft portion 312B, and may be formed ofelastomeric material or a molded inelastic material.

Proximal shaft portion 312A may be relatively stiff and may be formed ofa metallic tube such as a stainless steel hypotube. Distal shaft portion312B may be relatively flexible and may be formed of a polymeric tube,for example. To facilitate advancement of the flexible distal shaftportion 312B and the balloon 314, a core wire may be connected to andextend from the distal end of the proximal shaft portion 312A. The corewire 320 may comprise a metal wire such as a tapered stainless steelmandrel.

Core wire 320 extends to the distal end of the balloon 314, and mayextend beyond with an atraumatic spring tip, for example. The distal endof the balloon 314 may be bonded to the core wire 320, and the proximalend of the balloon 314 may be bonded to the distal end of the distalshaft portion 312B. Within the shaft 312 is a lumen through whichinflation medium is infused to inflate balloon 314.

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departures in form anddetail may be made without departing from the scope and spirit of thepresent invention as described in the appended claims.

1-28. (canceled)
 29. A system for stabilizing an electrical lead in acoronary vessel, comprising: an electrical lead having a proximalportion and a distal portion with a lumen extending therethrough; and anintravascular anchoring device including an anchor and an elongatetether, the tether detachably connected to the anchor and extendingproximally from the anchor, the tether extending through the lumen ofthe lead with the anchor disposed distally of the lead, wherein the leadis longitudinally movable with respect to the anchoring device.
 30. Asystem as in claim 29, further comprising a connector for limitinglongitudinal movement between the lead and the anchoring device, whereinthe connector is insertable into the lumen of the lead adjacent thetether.
 31. A system as in claim 29, wherein the tether innonelectrically conductive.
 32. A system as in claim 29, wherein thetether comprises a braid.
 33. A system as in claim 29, wherein thetether comprises a polymeric braid.
 34. A system as in claim 29, whereinthe anchor comprises a self-expanding structure.
 35. A system forstabilizing an electrical lead in a coronary vessel, comprising: anelectrical lead having a proximal portion and a distal portion with alumen extending therethrough; and an intravascular anchoring deviceincluding a self-expanding anchor and an elongate tether, the tetherconnected to the anchor and extending proximally from the anchor, thetether extending through the lumen of the lead with the anchor disposeddistally of the lead, wherein the lead is longitudinally movable withrespect to the anchoring device.
 36. A system as in claim 35, furthercomprising a connector for limiting longitudinal movement between thelead and the anchoring device, wherein the connector is insertable intothe lumen of the lead adjacent the tether.
 37. A system as in claim 35,wherein the tether in non-electrically conductive.
 38. A system as inclaim 35, wherein the tether comprises a braid.
 39. A system as in claim35, wherein the tether comprises a polymeric braid.
 40. A system as inclaim 35, wherein the tether is detachable from the anchor.
 41. A systemfor stabilizing an electrical lead in a coronary vessel, comprising: anelectrical lead having a proximal portion and a distal portion with alumen extending therethrough; and an intravascular anchoring deviceincluding an anchor and an elongate non-electrically conductive tether,the tether connected to the anchor and extending proximally from theanchor, the tether extending through the lumen of the lead with theanchor disposed distally of the lead, wherein the connector isinsertable into the lumen of the lead adjacent the tether.
 42. A systemas in claim 41, further comprising a connector for limiting longitudinalmovement between the lead and the anchoring device, wherein theconnector is insertable into the lumen of the lead adjacent the tether.43. A system as in claim 41, wherein the anchor comprises aself-expanding structure.
 44. A system as in claim 41, wherein thetether comprises a braid.
 45. A system as in claim 41, wherein thetether comprises a polymeric braid.
 46. A system as in claim 41, whereinthe tether is detachable from the anchor.